The invention concerns a device for exhausting the fumes forming inside accumulator batteries.
It is a known fact that, particularly in lead accumulator batteries, during their working stage and/or during the recharging stage, fumes form which must be exhausted since, if that is not done, they would cause an inflating of the accumulator with the consequent possible breakage of the same. For this reason the lids are provided with exhaust ducts which connect with one another the refill openings of the accumulator which are made on the lid and open them to the exterior through outlet openings In one or more of said outlet openings a joint complete with a hose is provided for the conveyance of the fumes to the exterior.
Since the fumes forming inside the accumulator also contain highly explosive hydrogen, in some cases it is necessary to also apply an anti-explosion device which, should flames or sparkles be present in the room around the accumulator, has the purpose of preventing the flames or the sparks from entering into the accumulator through the exhaust ducts and causing the explosion by igniting the fumes which are present within the exhaust ducts of the lid. Said anti-explosion device consists of a paste according to a known technique which is made of a material allowing the fumes inside the accumulator to be exhausted, but preventing the entrance into the exhaust ducts of the lid of eventual flames and sparks, which would cause its explosion.
In some constructions this anti-explosion paste is held in a container which is an integral part of the joint applied in the opening of the exhaust duct. In particular, said paste is arranged between the union connecting the joint with the outlet opening of the exhaust duct and the hose conveying the fumes away from the accumulator.
On the other hand, in some other embodiments according to the known technique, the anti-explosion paste is part of the lid of the accumulator and it is positioned within a chamber near the outlet opening of the exhaust ducts.
In both types of embodiment there is the inconvenience that, since the anti-explosion paste is permeable to fumes but not to liquids, it clogs up whenever the condensation resulting from the electrolyte liquid, which is led into the fume-exhaust ducts in the form of vapor, comes to rest on the point of connection of the paste. It is easy to understand how such an occurrence can cause remarkable inconveniences and also dangers, since, if this occurs, the fumes are not let out and they build up inside the accumulator. This causes, as has already been said, the inflating of the accumulator and its ensuing deformation.